The Earthman said, cautiously, “I remember the incident to which you refer, but I still don’t remember you.”

“I wondered then how anyone could possibly object to the Electron Pump on scientific grounds. You impressed me sufficiently so that when I saw you on the ship, something stirred; and then, eventually, it came back. I have not referred to the passenger list but let me check my memory. Aren’t you Dr. Benjamin Andrew Denison?”

The Earthman sighed. “Benjamin Allan Denison. Yes. But why does this come up now? The truth is, Commissioner, I don’t want to drag up matters of the past. I’m here on the Moon and rather anxious to start again; from the start, if necessary. Damn it, I considered changing my name.”

“That wouldn’t have helped. It was your face I recognized. I have no objection to your new life, Dr. Denison. I would not in any way interfere. But I would like to pry a little for reasons that do not directly involve you. I don’t remember, quite, your objection to the Electron Pump. Could you tell me?”

Denison’s head bent. The silence lengthened itself and the Commissioner-Appointee did not interrupt. He even stifled a small clearing of the throat.

Denison said, “Truly, it was nothing. It was a guess I made; a fear about the alteration in the intensity of the strong nuclear field. Nothing!”

“Nothing?” Gottstein did clear his throat now. “Please don’t mind if I strive to understand this. I told you that you interested me at the time. I was unable to follow it up then and I doubt that I could dig the information out of the records now. The whole thing is classified—the senator did very poorly at the time and he isn’t interested in publicity over it. Still, some details come back. You were once a colleague of Hallam’s; you were not a physicist.”

“That’s right. I was a radiochemist. So was he.”

“Stop me if I remember incorrectly, but your early record was a very good one, right?”

“There were objective criteria in my favor. I had no illusions about myself. I was a brilliant worker.”

“Amazing how it comes back. Hallam, on the other hand, was not.”

“Not particularly.”

“And yet afterward things did not go well with you. In fact, when we interviewed you—I think you volunteered to see us—you were working for a toy manufacturer—”

“Cosmetics,” said Denison, in a strangled voice. “Male cosmetics. That didn’t help gain me a respectful hearing.”

“No, it wouldn’t. I’m sorry. You were a salesman.”

“Sales manager. I was still brilliant, I rose to vice-president before breaking off and coming to the Moon.”

“Did Hallam have something to do with that? I mean with you leaving science?”

“Commissioner,” said Denison. “Please! It really doesn’t matter any longer. I was there when Hallam first discovered the tungsten conversion and when the chain of events began that led to the Electron Pump. Exactly what would have happened if I had not been there, I can’t say. Hallam and I might both have been dead of radiation poisoning a month later or of a nuclear explosion six weeks later. I don’t know. But I was there and, partly because of me, Hallam is what he is now; and because of my part in it, I am what I am now. The hell with the details. Does that satisfy you? Because it will have to.”

“I think it satisfies me. You had a personal grudge against Hallam, then?”

“I certainly had no affection for him, in those days. I have no affection for him now, for that matter.”

“Would you say, then, that your objection to the Electron Pump was inspired by your anxiety to destroy Hallam.”

Denison said, “I object to this cross-examination.”

“Please? Nothing of what I ask is intended to be used against you. This is for my own benefit because I am concerned about the Pump and about a number of things.”

“Well, then, I suppose you might work out some emotional involvement. Because I disliked Hallam I was ready to believe that his popularity and greatness had a false foundation. I thought about the Electron Pump, hoping to find a flaw.”

“And you therefore found one?”

“No,” said Denison forcefully, bringing his fist down on the arm of the chair and moving perceptibly upward from his seat in reaction. “Not ‘therefore.’ I found a flaw but it was an honest one. Or so it seemed to me. I certainly didn’t invent a flaw merely to puncture Hallam.”

“No question of inventing, Doctor,” said Gottstein soothingly. “I don’t dream of making such an implication. Yet we all know that in trying to determine something on the boundary line of the known, it is necessary to make assumptions. The assumptions can be made over a gray area of uncertainty and one can shade them in one direction or another with perfect honesty, but in accord with—uh—the emotions of the moment. You made your assumptions, perhaps, on the anti-Hallam edge of the possible.”

“This is a profitless discussion, sir. At the time, I thought I had a valid point. However, I am not a physicist. I am—was—a radiochemist.”

“Hallam was a radiochemist, too, but he is now the most famous physicist in the world.”

“He’s still a radiochemist. A quarter-century out of date.”

“Not so, you. You worked hard to become a physicist.”

Denison smoldered. “You really investigated me.”

“I told you; you impressed me. Amazing how it comes back. But now I’ll pass on to something a little different. Do you know a physicist named Peter Lamont?”

Reluctantly—“I’ve met him.”

“Would you say he was brilliant, too?”

“I don’t know him well enough to say and I hate to overuse the word.”

“Would you say he knew what he was talking about?”

“Barring information to the contrary, I would say, yes.”

Carefully, the Commissioner leaned back in his seat. It had a spindly look about it and by Earth standards it would not have supported his weight. He said, “Would you care to say how you came to know Lamont? Was it by reputation only? Did you meet?”

Denison said, “We had some direct conversations. He was planning to write a history of the Electron Pump; how it started; a full account of all the legendary crap that’s grown up around it. I was flattered that Lamont came to me; that he seemed to have found out something about me. Damn it, Commissioner, I was flattered that he knew I was alive. But I couldn’t really say much. What would have been the use? I would have gained nothing but some sneers and I am tired of it; tired of brooding; tired of self-pity.”

“Do you know anything about what Lamont has been doing in the last few years?”

“What is it you’re thinking of, Commissioner?” asked Denison, cautiously.

“About a year ago, maybe a little more, Lamont spoke to Burt. I am not on the senator’s staff any longer, but we see each other occasionally. He talked to me about it. He was concerned. He thought Lamont might have made a valid point against the Electron Pump and yet could see no practical way of taking up the matter. I, too, was concerned—”

“Concern everywhere,” said Denison, sardonically.

“But now, I wonder. If Lamont talked to you and—”

“Stop! Stop right there, Commissioner. I think I see you sidling toward a point and I don’t want you to move any further. If you expect me to tell you that Lamont stole my idea, that once again I am being treated badly, you are wrong. Let me tell you as forcefully as I can; I had no valid theory. It was purely a guess. It worried me; I presented it; I was not believed; I was discouraged. Since I had no way of demonstrating its value, I gave up. I did not mention it in my discussion with Lamont; we never went past the early days of the Pump. What he came up with later, however much it may have resembled my guess, was arrived at independently. It seems to be much more solid and to be based on rigid mathematical analysis. I lay claim to no priority; to none.”

“You seem to know about Lament’s theory.”